In my own case it goes more like this.
Professionally I deal with clients, which means wearing a business suit and looking "professional". Personally I'd much prefer dealing with a scientist or engineer who dresses like a bum and never shaves but knows what he's talking about technically, rather than a very well-dressed guy who can "walk the walk and talk the talk" but is clueless. Of course there are some people who can more or less do both, but the point is, in technical matters, for me, if you can do the former, the second is irrelevant one way or the other.
But in this
obsessed world, I have to play the game too, so I do my best to look "professional".
PoLR is visible in that I'm never sure if I'm being successful or not. Many times I thought I was dressed ok with a good appearance, only for people to remark later on things like my suit actually looked old or worn, my glasses looked dirty, my tie wasn't 100% adjusted -- and the point is, I honestly don't notice this kind of thing, and don't trust my ability to notice them.
Personally I don't care, and I find it embarrassing that so many people do care and regard this kind of nonsense as part of being "professional". But the reality is that many people care, and this may have consequences. And I'm never sure whether I'm being successful or not in that regard.